Spectrophotometric determination of microgram amounts of tantalum with Victoria Blue B

Abstract

stituent on the alpha carbon, and it is indicated that such groups at this point enhance the amount of product obtained.A carboxyl group at this same carbon inhibits the reaction. The latter is illustrated by the inability of the amino acid phenylalanine to afford a product with a measurable amount of absorption at 287 µ (Table II). The requirement for a primary or secondary amine is indicated by the failure ofbenzphetamine to react. As a rule primary amines react much better than secondary amines. The requirements of the reaction establish a relatively high degree of specificity for the ßphenylethylamine structure.The sensitivity limit of the method is approximately 0.5 Atg/ml of specimen providing a 10-ml sample is used. The procedure of this report is as sensitive as the spectrophotometric methods for determining barbiturates (15). Barbiturates and amphetamines are often taken concomitantly, and now determination of both compounds at therapeutic levels in urine can be performed by spectrophotometric analysis.

Nonferrous metallurgy. II. Zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, and tungsten

“…The medola's blue complex was also extracted into chlorobenzene for the determination of tantalum in niobium (502). The victoria blue B complex was extracted into benzene (329) as was the crystal violet complex (107), and methyl isobutyl ketone was used as the extractant in the case of malachite green (230).…”

“…4-(2-Pyridylazo)resorcinol: Zr, Ti (680); rocks (223); U (667) Sulfochlorophenol S: study of reactions (555); U, W (173); rocks and minerals (72) Sulfonitrophenol M: study of conditions (557) H202: Pb, Bi (645) H202-l-(2-pyridylazo)-2-naphthol: study of conditions (344) CNS: study of conditions ( 150) CNS-V-benzoyl-V-phenylhydroxylamine: fissium (664) V-Cinnamoyl-A'-phenylhydroxylamine: study of conditions (166) Acid Chrome Violet K: heat-resistant alloys (151) Pyrogallol: Pt (200) Dibromogallic acid: study of reagents (8) Polyphenols and aminopolycarboxylic acids: study of reagents (9) Catechol and tertiary amine: study of extraction (488) Pyrocatechol and tribenzylamine: study of conditions H202-thiosulfate: study of conditions (389) Dibromogallic acid: study of reagents (8) Pyrocatechol: alkali tantalates (596) Pyrogallol: study of conditions (551) Phenylfluorone: Li, K (65) Butyl Rhodamine: Nb (696) Nile Blue A: steel, Nb (192) Meldola's Blue: Nb (502) Victoria Blue B: study of conditions (329) Malachite Green: Nb (230) Methyl Green: study of conditions (628) Crystal Violet: Nb (360); study of conditions (107) s-Diphenylcarbazide: study of solvent extraction (145, 580, 684); plating baths (455); silicates (339); rocks and minerals (188); water (64); wood (144,678); ash (178); organic substances (297); shellfish (454) Cr(III): ruby (233)…”